Multiple control apparatus



,.'c. A. BROOKS MULTIPLE CONTROL APPARATUS May3l, 1938.

Filed J l 18, '1929 Patented May 31, 1938 UNITED STATES PATENT OFFICEMULTIPLE CONTROL APPARATUS Application July 18', 1929, Serial No.379,163

46 Claims.

My invention relates to multiple control apparatus, and is particularlyadapted for, although not limited to, the control of the railway trackswitches and signals in a railway switching or interlocking layout.

One feature of my invention is the provision of means controlled byrailway trafic conditions for completing restoration, to the normalcondition, of manually controlled apparatus for controlling signals in arailway switching or interlocking layout.

I will describe one form of apparatus embodying my invention, and willthen point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form ofapparatus embodying my invention.

Referring to the drawing, the reference characters i, l l and Edesignate the track rails of a stretch of double track railwaycomprising two tracks Y and Z which are connected together by means of acrossover track X, one end of which terminates in a switch W and theother end of which terminates in a switch W Track Y is divided by meansof insulated joints 2 into section a-A, A-C and CD, and track Z issimilarly divided by means of insulated joints 2 into sections f-F, FGand G-H. Each of these sections is provided with a track circuit whichincludes a track relay designated by the reference character T with adistinguishing exponent and connected across the rails adjacent one endof the section, and which is supplied with current by a track battery 3connected across the rails adjacent the opposite end of the section.Sections a-A, CD, fF and G-I-I which are in the rear of signals locatedat A, C, F, and G, respectively, are known as approach sections, andsections A--C and F-G in which switches W are located are known asdetector track sections.

Signals designated by the reference characters S and S govern eastboundtraffic moves from location A, on track Y, that is, moves from locationA toward the right as shown in the drawing. Signal S governs eastboundmoves from location G over track Z. Signals S S and S similarly governwestbound moves on tracks Y and Z. Signal S governs moves over track Yfrom location A past location C, when switch W in its normal position asshown in the drawing. Signal S governs moves from location A overswitches W and W when these switches are reversed. Signal S is alsoemployed as a call-on signal to govern moves from location A over switchW normal, when traffic conditions prevent the displaying of a proceedindication by signal S Signal S governs westbound moves over switch W inits normal position as shown. Signal S similarly to signal S governsmoves over switches W and W reversed, and when traffic conditionsprevent the displaying of a proceed indication by signal S signal Sprovides a call-0n indication for moves over switch W in its normalposition. As here shown, each of the signals S is of the semaphore type.

Each of the switches W and W can be 0perated by any suitable means such,for example, as an electric motor. A polarized switch relay in becomesenergized by current of normal or reverse polarity, as a pole-changingdevice Q is in its normal position as shown or is in its reverseposition. The operating apparatus for switches W and W moves theseswitches to the normal or the reverse position, according as 20 switchrelay m is energized in the normal or the reverse direction.

Approach locking of switches W and W is accomplished by means of stickrelays designated by the reference letter P with distinguishing ex- .25ponents. Each of these stick relays is associ- 'ated with the signal orsignals at one of the 10- cations A, C, F, and G, respectively, and isso controlled as to become de-energized when the control apparatus foran associated signal becomes energized for causing the signal toindicate proceed. Each approach locking relay P can then again becomeenergized when the approach track section for the associated signal isunoccupied, or when a detector track section over which the signalgoverns is occupied, while the control apparatus for the signal isde-energized. In emergency, a time releasing device, designated by thereference character J with a distinguishing exponent, can be employedfor causing an approach locking relay P to become energized when thecontrol apparatus for the associated signal is do -energized.

Device Q is removed from the control of relay m when either of thedetector track sections A-C and ,F-G is occupied or when any of theapproach locking relays P is tie-energized. Relay m then continuesenergized by a stick circuit which includes one of its own polarcontacts and a back contact of a detector track section relay 0 T or ofan approach locking relay P.

An indication relay i is inserted in series with relay m in the stickcircuit for relay m An indication means, here shown as an electric lamp(1 is controlled by relay i.

A polarized switch indication relay K is so controlled by switches W andW as to be enorgized in the normal direction when both switches W and Ware in their normal position, and to be energized in the reversedirection when both switches W and W are in their reverse position.Control circuits for relay K, and operating circuits for switches W andW as controlled by switch relay m are well known and form no part of mypresent invention and are therefore omitted from the drawing.

Each signal is controlled by a signal relay designated by the referencecharacter R with an exponent corresponding to that of the referencecharacter S for the signal. The signal relays R are controlled by stickrelays each of which is designated by the reference character I with adistinguishing exponent. Each of these stick relays, as for examplerelay P, has a pick-up circuit which is controlled by a device, hereshown as a push button contact U which is closed when and only whenmanually held in its closed position, and has a stick circuit which iscontrolled by a detector track relay and by a device, here shown as apush button contact U which is closed at all times except when manuallyheld open. The signal relays R, in addition to being controlled byrelays I, are controlled by contacts operated by switch indication relayK, by track relays T, by approach locking relays P, and by time releasesJ.

In series with each signal relay R is an indication relay 1" with acorresponding exponent. In series with each relay R, at the opposite endof its control circuit, is another indication relay 7'? with adistinguishing exponent. Each relay 1' controls an indication means,here shown as an electric lamp and designated by the reference charactere with a corresponding exponent. Each relay rr also controls anindication means, here shown as an electric lamp and designated by thereference character ee with a corresponding exponent.

Pole-changing device Q, push button contacts U, and releasing devices Jmay be grouped together in some central location such, for example, asan interlocking tower. Indication lamps d, e and co should be so placedas to be convenient to the towerman in charge of the devices Q and J andof push button contacts U.

In the drawing, the contacts operated by the various relays or by thetime releases J are identified by numbers, such numbers having suitabledistinguishing exponents when such contacts are not shown adjacent therespective relay or release by which they are operated. The exponent foreach of these contact numbers comprises the reference character andexponent for the respective relay or release, for example, the exponentR for contact 4, shown in the circuit for relay P comprises referencecharacter R and its exponent 2 for signal relay R which operates contact4. Similarly, exponents J for contact l3 in the circuit'for relay Pcomprises reference character J and exponent I of time release J whichis shown in the circuit for relay P and which operates contact I3.

Having thus described, in general, the arrangement and location of thevarious parts comprising my invention, I will now describe in detail theoperation of the apparatus.

As shown in the drawing, all parts are in their normal condition, thatis, relays I are de-energized, pole-changer Q is in its normal position,and all track sections are clear. With relays I de-energized, relays Rare also de-energized, and hence each signal is indicating stop. Withrelays I and R de-energized and the approach track relays energized,approach locking relays P are energized. The circuit for relay P forexample, passes from terminal 13 of a source of current not shown in thedrawing, through con tacts 4 5*, 6 T, and the winding of relay P toterminal 0 of the same source of current. The stick circuit for relay Pis also closed and includes the path just traced for the pick-up circuitas far as contact 6 thence through contact l of relay P and the windingof relay P to terminal 0. With device Q in its normal position, withrelays T and T energized, and with approach relays P energized, switchrelay m is energized in the normal direction by its normal pick-upcircuit passing from terminal B, through contact 3 of device Q, contactSI of relay T contact 32 of relay T contacts 33 34 35 36 winding ofrelay m, contacts 3W 38 38 M 4| of relay T 42 of relay T and 43 ofdevice Q to terminal 0. With relay m energized in the normal direction,switches W and W are in their normal position, and hence relay K isenergized in the normal direction.

I will now assume that the towerman desires to clear signal S for a movealong track Y from location A past location C. He therefore depressespush button contact U completing the pick-up circuit for relay I whichpasses from terminal B, through contact U and the winding of relay I toterminal 0. Relay I upon becoming energized, completes its stick circuitpassing from terminal B, through push button contact U contact 38contact 49 of relay I and the winding of relay I to terminal 0. Relay Iupon becoming energized, opens, at its contact 6 the pick-up and stickcircuits for relay P and completes the pick-up circuit for relay Rpassing from terminal B, through the winding of relay TTZ, contacts 54,55 56 and 57 of relay K, 58, front point of contact 59 contact 60',winding of relay 1 contacts BI 62', 63 of relay R winding of relay R andcontacts M 65 and 66 of relay K, and 67 to terminal 0. Relay R thereforebecomes energized, causing the arm of signal S to be operated to itsproceed position by its operating circuit passing from terminal B,through contact 86 of relay R and the operating mechanism of signal S toterminal 0. Relay R upon becoming energized, opens its contact E in thepick-up and stick circuits for relay P which, having already beende-energized by the opening of contact 6 has already opened, at itsfront contacts 35 and 38, the normal pick-up circuit for relay m. Thenormal stick circuit for relay m is then completed through the backpoints of contacts 35 and 38 and passes from terminal B, through thewinding of relay 1', normal contact 44 of relay m, back point of contact35 contact 36 winding of relay m, contact 37", back point of contact 38,and normal contact 45 of relay m .to terminal 0.

Relay 2 now being energized causes indication lamp d to be lighted byits circuit passing from terminal B through contact 92 of relay 2', andlamp d to terminal 0. On account of the completion of the circuit forrelay R relays r and W are energized, and hence lamp e is lighted by itscircuit passing from terminal B, through contact 94 of relay T and lampe to terminal 0. On account of relay rr being energized, lamp ee is alsolighted by its circuit passing from ter- I contact U breaking the stickcircuit for relay minal B, through contact llll] of relay T11 and lampcc to terminal 0.

If a train now approaches signal S and then enters section A-C,ole-energizing relay T relay I becomes de-energized on. account of theopening of contact 48 which is operated by relay T Relay R thereforebecomes de-energized due to the opening of contacts 59 and M and hencethe arm of signal S returns to its stop position. The circuit for relayR being opened, relays 1' and 7"? are de-energized, causing lamps e andac to be extinguished. When the train enters section A-C, relay Pbecomes energized again by its pick-up circuit which is the same as thatpreviously traced except including contact 8 instead of contact 1 Withrelay P energized, a second normal stick circuit for relay m is nowcompleted, passing from terminal B, through the winding of relay 2',normal contact 44 of relay m, back point of contact 3! of relay Tcontact 32 of relay T contacts 33 M 35 36, winding of relay in, contacts31, 38 M M contact 3! of relay T back point of contact 42 of relay T andnormal contact 45 of relay m to terminal 0. When the train leavessection A-C, relay m is again energized by its normal pick-up circuit asalready traced. Relay 2' is therefore de-energized and lamp :1 isextinguished. After the train has left section a-A, the pick-up circuitfor relay P is again completed through contact l' as previously traced.It is clear from the foregoing that after an eastbound train leavessection C-D, all apparatus will again be in the normal condition withoutany action having been taken by the towerman after the closing of pushbutton contact U1 for causing signal S to display the proceedindication.

I will now assume that with all parts of the apparatus again in theirnormal condition, the towerman again clears signal S by depressing pushbutton contact U as previously described. If, after the arm of thesignal S has moved to the proceed position, the towerman should desireto return the arm of signal S to the stop position before a train enterssection a-A, he will depress push button contact U thereby breaking thestick circuit for relay I and causing relay 1 to become de-energized.Relay I thus being de-energized breaks the circuit for relay R and socauses the arm of signal S to return to the stop position. Relay P thenbecomes energized again by its pick-up circuit through contact 'I asalready traced.

I will next assume that all parts having again been returned to theirnormal condition, the towerman has again depressed push button contact Ucausing signal S to display the proceed indication and that, after atrain has entered section aA, the towerman wishes to return the arm ofsignal S to its stop position and clear signal S for a train to move inthe opposite direction. He therefore depresses push button then startthe operation of time releasing device J At the beginning of thisoperation of release J contact 58 in the circuit for relay R is openedand,'ai'ter the lapse of a measured interval of time, contact 9 ofrelease J closes, completing a pick-up circuit for relay P which is thesame as the pick-up circuit first traced for relay P except includingcontact 9 of release J instead of contact 1 Relay P being thus energizedcompletes its stick circuit as previously described, and the towermanthen returns release J to its normal condition, causing contact 9 in thepick-up circuit for relay P to open. Relay P however, continuesenergized by its stick circuit.

The towerman now depresses push button contact U causing relay I to beenergized by its pick-up circuit passing from terminal B, throughcontact U and the winding of relay 1 to terminal 0. Relay 1 uponbecoming energized, completes its stick circuit passing from terminal B,through push button contact U contact 48', contact 50 of relay I and thewinding of relay 1 to terminal 0. Relay R now becomes energized by itscircuit passing from terminal B, through the winding of relay T13,contacts M 59 ,58 5'! and 56 of relay K, front point of contact windingof relay r winding of relay R contact 61 contacts 66 and E5 of relay K,and the back point of contact 64 to terminal 0. Relay R thus beingenergized, signal S is operated to the proceed position by its circuitpassing from terminal B, through contact 39 of relay R and the mechanismof signal S to terminal 0. With relay I energized, relay P isde-energized due to the opening of contact I2 With relay P de-energized,another normal stick circuit for relay m is closed through the backpoints of contacts 38 and M Relay i is therefore again energized andlamp d is lighted. The energization of the circuit for relay R causesrelays r and M to close their front contacts, completing the lightingcircuits for lamps e and ee respectively.

If a train now passes signal S and enters section A-C, relay I willbecome de-energized by the opening of contact 48'. With relay Ideenergized, relay R and also relays r and T73 become de-energized.Relay P now becomes energized by its pick-up circuit passing fromterminal B, through contacts N I2 I5, and the winding of relay P toterminal 0. Relay P upon becoming energized, completes its stick circuitwhich includes its contact it insteadof contact i5 in the circuit justtraced. With relays T3 and TT de-energized, lamps e and e6 are againunlighted. When all sections again. become unoccupied, all apparatuswill again be in the nor-- -mal condition without any action on. thepart of the towerman subsequent to the closing of push button contact UI will now assume that all parts are again in their normal conditionexcept that section C-D is occupied, causing relay T to be de-energizedI will also assume that the towerman attempts to clear signal S byclosing push button contact U Relay I then becomes energized as alreadydescribed, closing its front contact 5t but the circuit for relay R. isstill open at contact 82' which is operated by relay T Relay Rtherefore, becomes energized by its circuit which follows the pathpreviously traced for relay R as far as contact fii thence through theback point of contact E2, contact 18 of relay R the winding of relay Rand contacts M 65 and 66 of relay K, and 87 to terminal 0. Relay R thusbecoming energized causes the arm of signal S to be operated to thecall-on position by its circuit passing from terminal B, through contact8'! of relay R and the mechanism of signal S to terminal 0. A train uponpassing signal S and entering section AC causes relay I to bedeenerg-ized as already described. Relay R then becomes de-energized,causing signal S to again display the stop indication. When all tracksections are again clear, all apparatus will again be in the normalcondition without any action on the part of the towerman subsequent tohis closing of push button contact U I will now assume that with allparts again in their normal condition, thetowerman wishes to send atrain from track Y to track Z over crossover X. In order to reverseswitches W and W he moves device Q to its reverse position, therebycausing current of reverse polarity to be supplied to relay m throughthe reverse points of contacts 30 and 43 of device Q. Relay m thereforecloses its reverse polar contacts, and hence switches W and W are causedto move to their reverse position by their reverse operating circuitwhich includes contact 46 and the reverse contact 41 of relay m. Uponthe completion of the operation of switches W and W to their reverseposition, relay K becomes energized in the reverse-direction.

The towerman now depresses push button contact U causing relay I tobecome energized as already described, and completing a second circuitfor relay R passing from terminal B, through the winding of relay rrcontacts 68, 69 front contact 1| and reverse contacts 12 and 56 of relayK, contact '51 of relay K, contacts 58, 59 60 winding of relay 1'reverse contact BI contact 180i relay R winding of relay R contact 64front contact 65 and reverse contacts 66 and 15 of relay K, contact 16of relay K, and contact 1-1 to terminal 0. The operating circuit forsignal S is then completed at contact 8'! of relay R and the arm ofsignal S therefore moves to the proceed position. Energy supplied to thecircuit just traced for relay R. also energizes relays M and r causinglamps ee and e to be lighted by their circuits through contacts 98 and94, respectively.

After the train moves over crossover X and all track sections have againbecome unoccupied, all parts of the apparatus except those for thecontrol, indication and operation of switches W and W are returned tothe normal condition without further action by the towerman. In order toreturn switches W and W to the 'normal position, the towerman mustreturn device Q to its normal position, thereby causing current ofnormal polarity to again be supplied to the circuit for relay m. Relay mbeing thus energized in the normal direction causes switches W and W tobe returned to their normal position, and relay K then becomes energizedin the normal direction. When returning switches W and W to the normalposition as thus described, it is. not necessary for the towerman towaitto operate device Q until the train has moved off of sections AC and FG,for one of the reverse stick circuits for relay m through reversecontacts 44 and 45 of relay m will prevent a change in direction ofenergization of relay m as long as the train occupies one of thesesections. As soon as the train has left these sections, the change indirection of energization of relay m will be efiecfected without furtheraction by the towerman "after returning device Q to its normal position.

I will next assume that all parts having again been returned to theirnormal condition, the towerman has'again-reversed switches W and W andcleared signal S for a move from track Y to track Z over crossover X. Ifthen, after a train has entered section, a-A, the towerman should desireto send the train along stretch Y 'over switch W normal instead of totrack Z overswitches W and W reversed, he will first depress push buttoncontact U thereby causing relay I to become de-energized. Relay I uponbecoming :de-energized, causes relay R to also be de-energized. In orderto complete a pick-up circuit for relay P, the towerman will now operatetime releasing device J as previously described. Upon the energizationof relay P the towerman can complete the normal pick-up circuit forrelay m by returning device Q to its normal position. Switches W and Wwill then be returned to their normal position as previously described.The towerman will now close push button contact U thereby causing relayI and in turn relay R to be energized and signal S to display theproceed indication.

From the foregoing description of a few typical traffic moves, theoperation of the apparatus embodying my invention for every otherpossible be of very simple construction such, for example,

as that of ordinary push button circuit controllers. It will also beclear that, after a signal has beenoperated to its proceed position ascontrolled by the operation of one of these push button circuitcontrollers, a train upon moving past the signal and then clearing allthe associated track sections restores the apparatus to the normalcondition without further action by the towerman.

Although I have herein shown and described only one form of multiplecontrol apparatus embodying my invention, it is understood that variouschanges and modifications may be made therein within the scope of theappended claims without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

1. A railway interlocking system comprising a plurality of railwaytrafiic governing devices, a plurality of stick relays, a plurality ofcontacts each of which is open except when manually held closed, aplurality of second contacts each of circuit for each of said stickrelays controlled by one of said second contacts, means controlled byeach of said stick relays for controlling one of said governing devices,and means controlled by each of said stick relays for preventing thecontrol of another of said governing devices by another of said stickrelays.

2'. In combination with a plurality of railway traffice governingdevices, a main circuit path, a branch path for each of'said devices, acircuit for controlling each-of said devices including a correspondingbranch path and said main path, an

indi'ca'tionrelay included in said main path, an indication relayincluded in each of said branch paths respectively, and indication meanscontrolled by each of said indication relays.

3. ln combination with a plurality of railway trafiic governing devices,a source of current, a main circuit including said source, a pluralityof branch paths, a circuit including said main circuit and one of saidbranch paths for controlling each of said devices respectively,indication means controlled by each of said branch paths respectively,and indication means controlled by said main circuit.

4. In combination with a stretch of railway track containing a switch, asignal, a second signal, a circuit for controlling said first signalwhen said switch is in a given position, a second circuit forcontrolling said second signal when said switch is in a second position,an indication means controlled by said first circuit, a secondindication means controlled by said second circuit, and a thirdindication means controlled by both said first and said second circuits.

5. In combination, a polarized relay, a normal and a reverse pick-upcircuit for said relay, a stick circuit for said relay includingone ofits own polar contacts and an indication relay, and indication meanscontrolled by said indication relay.

6. In combination with a stretch of railway track, a first and a secondsignal for governing trafiic movements in opposite directionsrespectively over said stretch, an approach track circuit for said firstsignal including a track relay, a time release having a normally closedcontact as well. as a normally open contact which becomes closed uponthe lapse of a measured in terval of time after said first contactopens, a manually controlled circuit for controlling said first signal,a stick relay, a pick-up circuit for said stick relay including a frontcontact of said approach track relay and closed only when said firstsignal is controlled to indicate stop, a branch path for said pick-upcircuit including said normally open time release contact connected inmultiple with said front contact of the approach track relay, a stickcircuit for said stick relay closed only when said first signal iscontrolled to indicate stop, and a circuit including said normallyclosed time release contact and a front contact of said stick relay forcontrolling said second signal.

7. In combination, a railway trafiic governing device, a track sectionhaving a track circuit including a track relay, a stick relay, a contactwhich opens except when manually held closed, a second contact whichcloses except when manually held open, a pick-up circuit for said stickrelay including said first contact, a stick circuit for said stick relayincluding said second contact and controlled by said track relay, andmeans controlled by said stick relay for controlling said trafiicgoverning device.

8. In combination, a stick relay, a control instrument, an indicationdevice, a pick-up circuit controlled by said instrument in a givencondition for energizing said relay but not said indication device, anda stick circuit for said relay controlled by said instrument in a secondcondition and including said device in series with said relay forcontrolling said device as well as said relay.

9. In combination, a stick relay, a pick-up circuit for energizing saidrelay, a stick circuit for said relay, an indication device, and asecond relay the operating winding of which is included in said stickcircuit but not in said pick-up circuit for controlling said indicationdevice.

10. In combination, a stretch of railway track comprising a first and asecond approach track section and an intermediate switch section, atrack switch in said switch section, a signal adjacent one end of saidswitch section for governing traffic movements in a given direction oversaid switch, a control device for controlling said signal, a secondsignal adjacent the opposite end of said switch section for governingtraffic movements in theopposite direction over said switch, a secondcontrol device for controlling said second signal, an approach lockingrelay controlled by traffic conditions in said first approach sectionand in said switch section as well by said first signal control device,a second approach locking relay controlled by traffic conditions in saidsecond approach section and in said switch section as well as by saidsecond signal controldevice, means controlled by said first approachlocking relay for controlling said switch and said second signal, andmeans controlled by said second approach locking relay for controllingsaid switch and said first signal.

11. In combination, a stretch of railway track comprising a first and asecond approach track section as well as a switch section one end ofwhich adjoins an end of said first approach section and a second end ofwhich adjoins an end of said second approach section, a track switch insaid switch section, a signal adjacent said first end of said switchsection for governing traffic movements from a given direction over saidswitch, a control device for controlling said signal, a second signaladjacent said second end of said switch section for governing trafiicmovements from a second direction over said switch, a second controldevice for controlling said second signal, an approach locking relaycontrolled by traffic conditions in said first approach section and bysaid first signal control device, a second approach locking relaycontrolled by trafiic conditions in said second approach section and bysaid second signal control device, means controlled by said firstapproach locking relay for controlling said switch and said secondsignal, and means controlled by said second approach locking relay forcontrolling said switch and said first signal.

12. In combination, a section of railway track containing a switch, asignal adjacent one end of said section for governing traffic movementsover said switch, a control device for controlling said signal, a secondsignal adjacent a second end of said section for governing trafficmovements over said switch, a second control device for controlling saidsecond signal, a stick relay having a pick-up and a stick circuit one ofwhich is controlled by said first signal control device and the other ofwhich is controlled by trafiic conditions in said section, a secondstick relay having a pick-up and a stick circuit one of which iscontrolled by said second signal control device and the other of whichis controlled by traffic conditions in. said section, means controlledby said first stick relay for controlling said switch and said secondsignal, and means controlled by said second stick relay for controllingsaid switch and said first signal.

13. In combination, a railway track switch, a signal for governingtraffic movements over said switch, a second signal for governingtraffic movements over said switch, an approach looking relay controlledby traffic conditions associated with said first signal, a secondapproach locking relay controlled by traffic conditions as sociated withsaid second signal, means controlled by said fllst approach lockingrelay for controlling said second signal, means controlled by saidsecond approach locking relay for controlling said first signal, andmeans controlled by said first and second approach locking relays forcontrolling said switch.

14. In combination, a railway track switch, a signal for governingtraffic movements over said switch, a second signal for governingtraific movements over said switch, an approach locking relay controlledby traflic conditions associated with said first signal, a secondapproach locking relay controlled by traffic conditions associated withsaid second signal, means for clearing said first signal only if saidsecond approach locking relay is energized, means for clearing saidsecond signal only if said first approach locking relay is energized,and means energized for controlling said switch if and only if both saidapproach locking relays are energized.

15. In combination, a stretch of railway track including a switch, asignal control instrument, a second signal control instrument, anapproach locking relay controlled by said first instrument and by atrain in said stretch, a second approach locking relay controlled bysaid second instrument and by a train in said stretch, a signalcontrolled by said second approach locking relay and by said firstinstrument for governing traffic movements over said switch, a secondsignal controlled by said first approach locking relay and by saidsecond instrument for governing trafiic movements over said switch, andmeans controlled by said first and second approach looking relays forcontrolling said switch.

16. In combination, a stretch of railway track including a switch, asignal control instrument, a second signal control instrument, a stickrelay having a pick-up and a stick circuit one of which is controlled bysaid first instrument and the other of which is controlled by a train insaid stretch, a second stick relay having a pick-up and a stick circuitone of which is controlled by said second instrument and the other ofwhich is controlled by a train in said stretch, a signal controlled bysaid second stick relay and by said first instrument for governingtrafiic movements over said switch, a second signal controlled by saidfirst stick relay and by said second instrument for governing trafiicmovements over said switch, and means controlled by said first andsecond stick relays for controlling said switch.

1'7. In combination, a polarized relay, a normal and a reverse pick-upcircuit for said relay, a plurality of stick circuits for said relayeach of which includes a polar contact of said relay, and indicationmeans energized if and only if one of said stick circuits is energized.

18. In combination, a circuit extending between two trafiic governingrelays respectively associated with the opposite ends of a section ofrailway track over which trafiic is to move in either direction, acurrent source at each end of the circuit for supplying current to saidcircuit but normally disconnected therefrom, a central office controlledrelay associated with each end of the circuit, means governed by eachcentral ofiice controlled relay when energized to connect the associatedcurrent source with said circuit, and signals governed by the trafiicgoverning relays to permit traific to move through the section in adirection determined by the end at which said circuit is supplied withcurrent.

19. In combination, a circuit extending between two trafiic governingrelays respectively associated with the opposite ends of a section ofrailway track over which traflic is to move in either direction andcontaining a track switch, a current source at each end of the circuitfor supplying current to said circuit but normally disconnectedtherefrom, a central ofiice controlled relay associated with each end ofthe circuit,

means governed by each central office controlled relay when energized toconnect the associated current source with said circuit, signalsgoverned by the traffilc governing relays to permit tralfic to movethrough the section in a direction determined by the end at which saidcircuit is supplied with current, and contacts in said circuit assuminga position in accordance with the position assumed by said track switch.

20. Incombination, a stretch of track, a signal at each'e-nd of saidstretch for governing the movement of traflic into said stretch fromthat end, a signal governing relay associated with each of said signalsand when. energized permitting the associated signal to indicateproceed, another relay manually controlled from a central ofiiceassociated with each of said signals, a movable contact on each of saidanother relays, said movable contacts being connected by a partialcircuit and said movable contacts if in one position connecting saidpartial circuit to the associated signal governing relay and if inanother position connecting said partial circuit to a source of current,whereby both of said trafiic governing relays may be controlled over thesame partial circuit and only one of said signal governing relays may beenergized at one time.

21'. In an interlocking system for railroads, one track section having atrack switch, another track section having a track switch, signal meansgoverning trafiic in both directions over said one track section, signalmeans governing trafiic in both directions over said other tracksection, one directional stick route relay associated with said onetracksec'tion being deenergized with said signal means for said onetrack section cleared for traific in one direction, and means preventingthe clearing of said signal means for said other track section in adirection in opposition to the direction established in said one tracksection, said means including said one directional stick route: relay.

22. In combination, a stretch of railway track, a signal at each end ofsaid stretch each governing movement of traflic into said stretch, atrack switch at an intermediate point in said stretch, a route wireextending from one to the other of said signals and including a contactclosed only if said switch is in a position to establish a route oversaid stretch and connected at each end to the same terminal of a sourceof current, contacts at each of said signals reflecting trafiicconditions and normally included in said route wire, a route relayassociated with each of said signals for controlling such signal, andmanually controllable means at each route relay for substituting suchroute relay for the associated trafiic reflecting contacts andconnecting that end of said route wire to the other terminal of saidsource.

23. In combination, a stretch of railway track, a signal at each end ofsaid stretch each governing movement of trafiiic into said stretch, atrack switch at an intermediate point in said stretch, a route wireextending from one to the other of said signals and including a contactclosed only if said switch is in a position, to establish a route oversaid stretch and connected at each end to the same terminal of a sourceof current, a route relay associated with each of said signals forcontrolling such signal, and manually controllable means for each routerelay for connecting that end of the route wire to the opposite terminalof said source and including the associated relay in said route wire.

24. In combination, a stretch of railway track, a signal at each end ofsaid stretch each governing movement of traffic into said stretch, atrack switch at an intermediate point in said stretch, a route wireextending from one to the other of said signals and including a contactclosed only if said switch is in a position to establish a route oversaid stretch and connected at each end to the same terminal of a sourceof current, a route relay associated with each of said signals forcontrolling such signal, manually controllable means for each routerelay for connecting that end of the route Wire to the opposite terminalof said source and including the associated relay in said route wire,and trafiic controlled contacts included in said route wire.

25. In combination; a stretch of railway track; a signal at each end ofsaid stretch, each govern ing movement of traffic into said stretch;manual control means for each of said signals; a track switch at anintermediate point in said stretch of track; manual control means forsaid track switch; and a time element means for each of said signalseifective, when a train is in approach to that signal, to prevent boththe response of said track switch to its manual control and the responseof said other signal to its manual control means for a predeterminedtime after that signal having a train in approach thereto has beencaused to display stop by its manual control means.

26. In combination; a stretch of railway track;

a signal at each end of said stretch, each governsaid track switch; anda time element means for each of said signals effective, when a train isin approach to a signal, to prevent both the response of said trackswitch to its lever and the response of said other signal to its leverfor a predetermined time after the first signal has been caused todisplay stop by its lever.

27. In combination; a stretch of railway track; a signal at one end ofsaid stretch governing the entrance of trafiic into said stretch fromthat end by indicating proceed or stop; a signal at the other end ofsaid stretch governing the entrance of trafiic into said stretch fromthat end by indicating proceed or stop; a free and unlockable manualdevice for each of said signals, each of said manual devices socontrolling its respective signal that it may always be caused toindicate stop, but can be caused to indicate proceed only when trafficconditions are proper in said stretch; and a manually controllable timemeasuring means associated with each of said signals, each of said timemeasuring means being at times effective, upon being operated, tomeasure ofi a predetermined time before the opposite one of said signalscan be caused to indicate proceed in accordance with traffic conditions.

28. In a relay interlocking system for railroads, two opposing signalsat opposite ends of a stretch of single track, a manually controlledrelay for each signal; a control circuit for each signal closed onlywhen the manually controlled relay for such signal is energized, themanually controlled relay for the opposing signal is deenergized, andthe opposing signal is in its stop position; and manually controllableapproach looking means adjacent each signal and effective when operated,to prevent the clearing of the opposing signal until the first signalhas been in the stop position for at least a predetermined time intervalprovided a train was approaching said first signal within apredetermined distance when it assumed the stop position.

29. In combination, a stretch of railway track, a signal for governingtraffic movements over said stretch, an electrorespo-nsive device forcontrolling the signal, a stick relay, a pickup circuit for said stickrelay controlled by traffic conditions, a stick circuit for said stickrelay controlled by said electroresponsive device, a second signal forgoverning trafiic movements over said stretch, and means requiring saidstick relay to be energized for clearing said second signal.

30. In combination, a stretch of railway track, a track circuit for saidstretch including a track relay, a signal for governing trafiicmovements over said stretch, a signal relay for controlling said signal,a stick relay, a pickup circuit and a stick circuit for said stick relayone of which is controlled by said track relay and the other of which iscontrolled by said signal relay, a second signal for governing trafiicmovements over said stretch, and means for causing said second signal todisplay a proceed indication only when said stick relay is energized.

31. In combination, a stretch of railway track, a track circuit for saidstretch including a track relay, a signal for governing trafiicmovements over said stretch, a stick relay, a manually controlled relay,a circuit including a front contact of said manually controlled relayfor at times causing said signal to displaya proceed indication, apickup and a stick circuit for said stick relay one of which iscontrolled by said track relay and both of which are controlled by aback contact of said manually controlled relay, a second signal forgoverning trafiic movements over said stretch, and means for causingsaid second signal to display a proceed indication only when said stickrelay is energized.

32. In combination, a stretch of railway track, a signal for governingtraific movements over said stretch, an electroresponsive device forcontrolling said signal, a second signal for governing trafiic movementsover said stretch, a stick relay, a time releasing instrument, a pickupcircuit and a stick circuit for said stick relay one of which iscontrolled by said instrument and the other of which is controlled bysaid electroresponsive device, and means for causing said second signalto indicate proceed efiective only when said stick relay is energized.

33. In combination, a stretch of railway track, a signal for governingtraffic movements over said stretch, a signal relay for controlling saidsignal, a second signal for governing traffio movements over saidstretch, a stick relay, a time releasing instrument, a pickup circuitand a stick circuit for said stick relay one of Which is controlled bysaid instrument and the other of which is controlled by said signalrelay, a second signal relay, a circuit including a front contact ofsaid stick relay for controlling said second signal relay, and a circuitincluding a front contact of said second signal relay for controllingsaid second signal.

34. In combination, a stretch of railway track, two conflicting signalsfor governing the movement of traffic over the stretch, manuallyoperable means for controlling said signals, an approach locking stickrelay, an energizing circuit for said stick relay closed only when onesaid signal is at stop, means for delaying the closing of said circuitfor a predetermined time interval after said one signal is put to stop,means for cancelling said delay if there is no train approaching withina predetermined distance of said one signal, and a control circuit forenergizing said other signal closed only when said stick relay isenergized.

35. In combination, a stretch of railway track, two conflicting signalsfor governing traffic movements over said stretch, manually operablemeans for controlling said signals, an approach locking stick relay foreach signal, an energizing circuit for each stick relay closed only whenthe corresponding signal is at stop, means for delaying the closing ofsuch circuit for a predetermined time interval after the correspondingsignal has been put to stop, means for cancelling said delay if there isno train approaching with in a predetermined distance of the signal, andcontrol circuits for each of said signals closed only when the stickrelay for the other signal is energized.

36. In an interlocking system for railroads, a railroad track switch, aswitch machine for operating said track switch, a free and unlockablelever for controlling said switch machine, a signal for governingtrafiic over said track switch, a signal lever operable manually tocause said signal to indicate clear, approach locking means preventingoperation of said switch machine in response to a change in the positionof said first mentioned lever if said signal indicates clear, releasingmeans for releasing said approach looking means a predetermined timeafter said signal is manually caused to indicate stop whenever a trainis approaching said track switch, means automatically causing saidsignal to indicate stop upon the passage of a train over said trackswitch independently of said signal lever, and other means forimmediately releasing said approach locking means when said signal iscaused to be automatically put to stop, said other means being effectivecontinuously until said signal lever is again manually governed.

37. In combination, a stretch of railway track, a signal for governingtraffic movements in a given direction over said stretch, a secondsignal for governing traffic movements in the opposite direction oversaid stretch, a manually controlled relay, a control relay for saidfirst signal controlled by track circuit conditions in said stretch, anapproach locking relay associated With said first signal, a pick-up anda stick circuit for said approach locking relay one of which iscontrolled by a back contact of said manually controlled relay and theother of which is closed only while said first signal is controlled toindicate stop, means controlled by a front contact of said manuallycontrolled relay and by a front contact of said control relay forcontrolling said first signal to display a more favorable indicationthan stop, and a circuit controlled by a front contact of said approachlocking relay for controlling said second signal to display a morefavorable indication than stop.

38. In an interlocking system for railroads, a detector section ofrailroad track including a track switch, means for operating said trackswitch, a signal for governing the movement of trafic through saiddetector section, manually operable means for causing said signal toindicate clear or stop, atrack relay for said detector section, a stickrelay having a pick-up circuit closed in response to an operation ofsaid manually operable means and a stick circuit including a frontcontact of said track relay, a circuit for controlling said signalincluding a contact closed only when the track relay is energized and asecond contact closed only when the stick relay is energized, a lockrelay which when deenergized prevents operation of the track switch, apick-up circuit for said lock relay closed when the signal is manuallyput to stop if there is no train approaching within a predetermineddistance oi the switch, a second pick-up circuit for said lock relayclosed only when the signal has been controlled to indicate stop for atleast a predetermined time interval, a third pick-up circuit for saidlock relay closed when the signal indicates stop due to the release ofsaid track relay, and a stick circuit for holding the lock relayenergized until the signal is again cleared.

39. In combination, a section of railway track over which traific maymove and containing a track switch, circuit portions associated withsaid section of track so as to extend from, one trafiic governing relayto either of two other traffie governing relays depending upon theposition of the track switch, means for completing a route circuitincluding some of said circuit portions to thereby energize a selectedtrafiic governing relay, signals governed by said trainc governingrelays to allow the movement of trafiic over said section, poweroperating means for the track switch, manual control means forcontrolling said power operating means, and means preventing response ofsaid power operating means to said manual control means when a routecircuit is energized.

40. In combination, a section of railway track over which traffic maymove and containing a track switch, circuit portions associated withsaid section of track so as to extend from one trafiic governing relayto either of two other traffie governing relays depending upon theposition of the track switch, means for completing a route circuitincluding some of said circuit portions to thereby energize a selectedtraiiic governing relay, signals governed by said traflic governingrelays to allow the movement of trailic over said section, poweroperating means for the track switch, manual control means forcontrolling said power operating means, and means preventing initiationof said power operating means in response to said manual control meanswhen a route circuit is energized but allowing the continuation of anoperation already initiated.

41. In combination, a section of railway track containing a track switchand over which traffic may move in either direction, circuit portionsassociated with said section of track so as to extend from one traificgoverning relay to either of two other traffic governing relaysdepending upon the position of the track switch, means for energizingselected ones of said traffic governing relays by completing circuitsincluding some of said circuit portions, signals governed by saidtrafiic governing relays to allow the movement of traiiic over saidsection in a direction depending on the direction of current flow insaid circuits for said trafiic governing relays, power operating meansfor the track switch, other means for controlling said power operatingmeans, and means preventing response of said power operating means toiii said other means when any one of said traffic governing relays isenergized.

42. In combination, a circuit extending between two t'rafiic governingrelays respectively associated with the opposite ends of a section ofrailway track over which traffic may move in either direction andcontaining a track switch, a source of current at each end of thecircuit for supplying current to said circuit, a manually controlledrelay associated with each end of said circuit, means governed by eachmanually controlled relay when energized to connect the associatedtraffic governing relay with said circuit, signals governed by saidtraffic governing relays to allow traffic to movethrough the section incorresponding directions, contacts in said circuit assuming a positionin accordance with the position assumed by the track switch, poweroperating means for the track switch, manually controlled means forgoverning the operation of said power operating means, and meanspreventing the response of said power operating means to said manuallycontrolled means when one of said trafiic governing relays is energized,whereby operation of said manually controlled means while one of saidtraffic governing relays is energized does not affect the control ofsaid signals.

43. In combination, a circuit extending between two trafiic governingrelays respectively associated with the opposite ends of a section ofrailway track over which trafiic may move in either direction andcontaining a track switch, a source of current at each end of thecircuit for supplying current to said circuit, a manually controlledrelay associated with each end of said circuit, means governed by eachmanually controlled relay when energized to connect the associatedtraffic governing relay with said circuit, signals governed by saidtrafiic governing relay to allow traflic to move through the section ina corresponding direction, contacts in said circuit assuming a positionin accordance with the position assumed by the track switch, poweroperating means for the track switch, manually controlled means forgoverning the operation of said power operating means, means preventingthe response of said power operating means to said manually controlledmeans when one of said traffic governing relays is energized, and meansallowing the response of said power operating means to said manuallycontrolled means following the deenergization of a traflic'governingrelay only at least a predetermined time thereafter if a train isapproaching the track switch, whereby operation of said manuallycontrolled means while one of said traffic governing relays is energizeddoes not affect the control of said signals, and whereby the operationof the track switch is at times delayed following the deenergization ofone of said traflic governing relays.

44. In a relay interlocking system for railroads, a track layoutcomprising a plurality of track sections capable of interconnection bytrack switches to form different tralfic routes, a signal at each end ofeach section for governing the movement of traffic into the section, aroute relay and a manually controlled relay for each signal, a circuitnetwork arranged as a counterpart of the track layout including aconductor for each track section and indication contacts controlled bythe track switches for interconnecting said conductors to form routecircuits each of which is a counterpart of a traffic route through thelayout, means for energizing each route relay over the route. circuitfor the route governed by the associated signal, comprising a frontcontact of the manually controlled relay .at the same end and a backcontact of the manually controlled relay at the opposite end of saidroute circuit, and a control circuit for each signal including a frontcontact of the associated route relay.

45. In a relay interlocking system for railroads, a track layoutincluding a plurality of track switches manually operable to formdifferent traffic routes, indication contacts repeating the positions ofthe track switches, a circuit network arranged as a counterpart of thetrack layout and including conductors interconnected by said contacts toform route circuits corresponding to the routes established by the trackswitches, a route relay and a manually operable relay at each end ofeach route circuit, a signal at each end of each route, a controlcircuit for clearing each signal controlled by the correspondingmanually operable relay and including the associated route relay and theroute circuit for the route governed by the signal, and means renderedeffective when a control circuit is closed to prevent the closing of thecontrol circuit for a selected one of a plurality of opposing signals,the selected signal being the one at the opposite end of the routeestablished by the track switches.

46. In combination, a railway track switch, a signal for governingtrafiic movements over said switch, a manually controllable switchcontrol de vice, a polarized switch control relay, circuits controlledby said switch control device in its normal and reverse positions forenergizing said polarized switch control relay in the normal and reversedirections respectively, means controlled by said polarized switchcontrol relay for operating said switch to its normal or its reverseposition according as said switch control relay is energized in thenormal or the reverse direction, a manually controllable signal controldevice having a normal and an operated position, a signal circuitcontrolled by said signal control device in its operated position and bysaid switch in a given position for clearing said signal, andelectro-responsive means controlled by said signal control device forremoving said switch control device from control of said polarizedswitch control relay when said signal control device is in its operatedposition and thereby preventing an operation of said switch controldevice from causing said signal to display a stop indication.

CHARLES A. BROOKS.

